I added in an isset CartController/AddPresetCV to make the session variable if it didnt exists. SiteController/Incoming now deals with links coming from potential employers. It takes the skill ids from the url (the url itself will be masked with url shorterner) and saves them to session. This means when they click add actual cv skills now, inside CartController/addPresetCV, it will use the session variable with those skill ids to generate the CV that's unique to them. If someone accesses the site normally, as in, without a tailored site/incoming link, it will just use the hardcoded preset like it used to always do.